Adjustable knee rest



July 21, 1959 R. L. MCDONALD ETAL 2,895,775

ADJUSTABLE KNEE REST Filed April 15, 1957 5 Sheets-Sheet l INVENTORY.

ROBERT L. WDONALD Alla KARL H BURZLAFF YMS ATTORNEY 1, 1959 R. MCDONALD ETAL 2,895,775

ADJUSTABLE KNEE REST 5 Sheets-Sheet 2 Filed April 15. 1957 INVENTORY. ROBERT L. M DONALD Alva KARL h. BURZLAFF ATTORNEY y 1959 R. L. MCDONALD ET AL 2,895,775

ADJUSTABLE. KNEE REST Filed April 15. 1957 5 Sheets-Sheet 3 28-. gnnnflguununmmm F ialmmnullinnnu E 23 i I Y a? [5% .28 I! 4;

37 76 INVENTORS. 44 43 ROBERT L. DONALD AND KARL Ii BURZLAFF H65 I WMWM ATTORNEY y 1959 R. L. MCDONALD ETAL 2,895,775

ADJUSTABLE KNEE REST Filed April 15, 1957 5 Sheets-Sheet 4 INVENTORS. ROBERT L MDO/VALD Y m w A TTORNEY AIID KARL Ii BURZLAFF y 1959 R. 1.. MCDONALD ET AL 2,895,775

ADJUSTABLE KNEE REST 5 Sheets-Sheet 5 Filed April 15, 1957 INVENTORS. R ROBERT L. M DONALD BY AND KARL H. BIJRZLAFF AYTORNEY 2,895,775 Patented July 21, 1959 nice 2,895,775 ADJUSTABLE KNEE REST Robert L. McDonald and Karl H. Burzlalf, Rochester, N.Y., assignors to Bitter Co., Inc., Rochester, N.Y., a corporation of Delaware Application April 15, 1951, Serial No. 652,939 Claims. (31. 311-5 This invention relates to an improvement in medical examination or operating tables and more particularly to an adjustable knee rest for such tables of the type described in McDonald Patent No. 2,764,459 and assigned to the assignee of'the present invention;

In medical examination or operating tables of the type such as described in the above mentioned patent, a detachable knee rest is generally provided on the table to facilitate examination, treatment, or operating by proctologists and the like. The knee rest is supported on a leg rest section and a patient may kneel on the knee rest with the lower front portion of his body below his waist in contact with the leg rest section and with the upper part of his body bent over the top of the leg rest section permitting the proper examination by the physician. 'I'he eifort is made to locate the patients body and internal organs by the patient bending at the waist to orient the patient properly for examination by the physician.

It can be readily understood that the variation in leg lengths from patient to patient means that the knee rest must be adjusted along the leg rest section for each patient in order to insure that the patients body when he bends at the waist will extend comfortably over the top of the leg rest section when the patient is in the kneeling position. In order to avoid moving the patient on and off the knee rest while making the proper adjustment of the knee rest in accordance with the physical proportions of the patient, it is highly desirable that the knee rest be capable-of adjustment while the patient is kneeling thereon Furthermore, often during operating or examination of the patient, it is necessary to shift the patients position 'which heretofore could only be accomplished by lowering the table and having the patient dismount from the knee rest. Lifting him manually while the knee rest adjustment is made and the table tilted is in most cases an arduous physicaltask for the doctor to perform. 7

Accordingly it is a primary object of this invention to provide a new and improved adjustable knee rest for medical examination or operating tables.

Another object of this invention is to provide a new and improved adjustable knee rest for the leg rest section of an articulated examination table which may be adjustably positioned to the correct height while the patient is supported thereon.

It is a further object of this invention to provide a new and improved detachable and adjustable knee rest for an articulated examination or operating table of the type used particularly by proctologists which may be readily moved to aselected position while the patient is supported on the table either preceding or during the examination, operation, or treatment whereby the patient is accurately positioned in the exact position required by the doctor. I 1

In the medical examination or operating tables of the type discussed above wherein a knee rest is employed as a component of. the table, the usefulness and adaptability of the table is further'improved by providing a knee rest which may be moved so as to lie substantially in.

the same plane as the table section or sectionsv to thus increase the overall length of the table and .adapt it for general office purposes. Such, an improvement has been suggested previously, as disclosed in the above patent. However, the usefulness of the table and the easing'of the doctor and nurses task is materially improved by incorporating such a feature in an adjustable knee rest. It is, therefore, a still further object of this invention to provide a new and improved adjustable knee rest for an examination table which" is readily adjustable throughout a selected range; which may be quickly and easily detached from the table when it is temporarily notneeded; and which maybe positioned so as to lie in the same plane as its associated table sections,

Other objects and advantages of the invention will be particularly set forth in the claims and will be apparent from the following description; when taken in connection.

with the accompanying drawings, in which:

Fig. 1 is a side elevation of a medical examination table in one position with the knee rest of the invention arranged to support a patient in the kneeling position; Fig. 2 is a view similar to Fig. "l'showing the table in the position conventionally used by proctologists for" examination or treatment;

Fig. 3 is an enlarged view ofa portionof the table of Fig. 1 showing the knee'rest with its cover plate removed for clarity; V I Fig. 4 is a fragmentary sectional'yiew taken substantially along line 44 of Fig. '3 in the direction indicated by the arrows; a I l 1 Fig. 5 is an end view partially in sectionof the table portion of Fig. 3;

Fig. 6 is a view similar to Fig. 3 showing the leg rest 1 in its lowermost position;

Fig. '7 is'a view similar to Fig.3 indicating how the knee rest is releasedand swung to the position where it lies in the same plane as its associated table sections toformanextensionf I A f Fig. 8 is aipar'tial view of the table'of Fig. l with the knee rest forming: an' extension of its associated table section; arid i v Fig; 9"is'an enlarged view ofa portion of the table of Fig. 8 including the knee rest. A

The knee rest of this invention is particularly adapted for use with the medical examination table described in Patent No. 2,764,459 mentioned above, and, as shown in the drawings, the knee rest has been shown as a component of such a table. However, the knee'rest is not necessarily limited to use with this'type of table "as it may be adapted to any other type of medical table in which it is desired to support the patient in a 'kneelin'g' or other position and where it is desirable that adjust I ments be made while the patient is in the supported position.

Referring now to Figs. 1 and 2,"the*knee"-'rest of this invention is incorporated in a medical examination or operating table of the type described in the above mentioned patent which is generally designated by the numeral 11. The table 11 comprises a main table section 12, a leg'rest section 13, ahead rest section 14 and a supporting base 16 The main table section 12 i s pivotally mounted at one end On a pair of cradle members. 17 which are carried by a bracket 18 supported as the base 16, The head rest section 14'may be adjustably positioned 'along the maintable section 12 by meansof indexing tracks 15.

The other end or the m m rable section la s'sup: ported on arms 19 which are connected for sliding move- I ment to the table section'bymeans such as a pinand slot joint designated generally by the numeral 35. It will b'e'partic'ula'rly not'dthatthe leg'rest season 13 and the main table section are not pivotally connected. The arms-1Q are; secured to; the supporting bracket 18 while e tadl im e u i ai e t u q bjr a effii j ted: f 20, by means of an hydraulic cylifldfi 21;. "The leg rest section 1 3 is pivotally mounted at he ppb fnd bf' h fadle mem e m the main" table secti n12, as indic ated at 25, and may be manually secured in any desired angular position by means of a lockingllever 22which. cooperates with a telescopic connection between the-cradle members 17 and th'e'freeI end of the legl rest section 13. A knee rest constructed in. ace ce. with invention is 1 shown associated withthefle t s 13 All'of. the t blsect ns may tiemoved vertically to fliedesired hyl fi hxdraul s; me hanism (n t hqwa) to ta ss i ssun p ti sl a eme d perated by means of the, ro Lle. i s-24.

y. w y- .1 stra .q s. tar-how t e.:- examination qblg', rzs atss wh n he able: in he. position: of isf j t e. a ent mwat t able... a. kneelin po tion on the knee rest 23; thth e lower front portion f is dy Q tast w h heesf e t se ion 13.. The patient then bends, his forward overthej-top .26.. of the leg, rest, ection 13 --inwha t;rnight betertnqd a-,jack n f 'PP F O s minsthe able is a th i general height levelde'sired by the-,doctor, h hydraulic c'ylinder 21 may then be operated by meansoflthemontrols 24 pi ot d memb r .1t aposit nrs ch as. that hQW n-Eiev t ullbe. no ed n Figt the free end of the main table section 12 hasmovedisomewhat belowthe top edge 2 6 ofithe leg rest; section 13 i he esu tt at he. pper p rt-of t pat n s y will extend downward at an angle. of course, by means of locking leven; 22, the angu ar position of the leg rest section 13 with respect to the main table section has been preset but normally the {right angle relation of. the sections is employed. However, regardless of'the. partieular angle chosen, the.upper;,edge}or top 26 will always lie above the free. endof. themain table section- 12 as hown. n' i 2-;

This particular movement of the articulated tableshown in Fig. 2 and described hasbeen'found necessary or at lcast extremely desirable, :in proctology and similar types of medical treatment. This positionis advantageous case s ,where,:for example, it is desired to use such instruments as a sigmoidoscopef when the patient is loeatedin the position on the" table shown in Fig. 2. The patients stomach muscles are relaxed. somewhat into the space indicated 81.30. His internal organs are moved into a properposition by..gravity to permit insertion ot a sigmoidoscope easily and reduce the hazard of puncturing the intestines.

It is highly important, however, that the patients body lie. when bent overthe. top .26.of.the leg rest section 13 in such a way to release. and relax the organs. The knee rest 23 must, therefore, be' positioned along the leg rest 13 in accordance with the length of the patients 8. 1; tha rs ip tssqhstru nras-sh above patent, it was often neeessary thatatrial and error l o 9 hdiustms trbs.uses a suiri g e patient to mountthetablewithhis on the knee rest a num-, fms u ti the. m re!" p'q t qa Q us ment could beobta.ined.f In so,.far as is known, none of the previous constructions permitted the; knee rest :tobe adjustedjwithf thep'atie'nt in the examination position (see Fig, oiifihe i table.

u h n prs, w e .the-tah suas' iygte e o exp s q fitEt-J rg q-t leatn nth rted, it often was necessary during the progress o f the treatthe t p; ,6... to e abl Shifting of the patient at this stage of the operation or treatment by making adjustments of'the knee rest became highly inconvenient if not impossible because the doctor had to bodily lift the patient. Almost invariably the doctor either compromised by continuing the treatment or operation with the patient in an unfavorable position or it was necessary to shift the table to the position of Fig. 1 and have the patient dismount to enable adjustment of the knee rest.

With the novel construction of this invention, the knee rest 23 has been so arranged that adjustment of its position on its associated leg rest section 13 may be made while thefull weight of the patient is supported eliminating the need for removing the patient once he has mounted thetable.

As specifically illustrative of the invention, the knee rest 23 comprises a cushion 27 to which is secured by meanssuch as screws-28, a pair. ot support arms 29; 31. These support arms 29, 31, extend outwardly from the cushion'f 27 to thickenedportions or support arm sections 32, 33 respectively which form a yoke, such as shown in Fig. 5, and are suitably; spaced to loosely accommodate. "the leg, restsec tion 13 therebetween. As the two support arms 29, '31are substantially identical in structure only support arm 29 will be described hereinatter. i

In order to support the knee rest 23 on the leg rest section 13, a guide track, designated generally by the numeral 34, is secured by means'such as screws 36 along each side. of'the leg. rest section 13 and extend longitudinally therewith. As shown best-in Fig. 4, each track 34 contains a-lower rail 37 and an upper rail 38 with which a gear rack 39'is preferably integrally formed.

Theinner face of:the thickenedarm portion 32 has been'cut away -at 41. tov accommodate upper and lower rollers 42, 43 (Fig. 4) which are suitably secured to portion 32 by means such asbolts 44. These rollers 42, 43 are spaced longitudinally of the track 34, as shown best in Fig. 3, so that the upper roller 42 rides on up per rail-38 and the lower roller 43 rolls on the lower rail 37.

Means have'been provided tomove the knee rest 23 along the guide tracks 34 in accordancewith the leg length of the patient who is to be mounted on the table. More specifically, a pinion 46 is connected to a spur gear 47 which is suitably journaled-within an opening 48in the support arm section 32. The pinion 46 is arranged to drivably engage withthe rack 39 on the upper guide rail. 38 as shown best-in Fig. 5.' The support arm section-32 is suitably recessed on its outer face at 49Jto accommodate the spur gear 47 and a driving gear train connected thereto consisting ofgears 51, 52' and 53, rigidly mounted upon shafts 54, 56 as shown. Gear 53 meshes with the'end ofan elongated drive gear 57 extending between the support cross sections 32, 33. The-gear 5 7is journaled in anysuitable manner atone end insection 33-and at its other endis provided with an integral extension 60 supportedlyengaged with an externally threaded tapered slotted bearing 55 fixedly mounted by meanssuch asbolts 50' on arm section 32. A nut 58 is threadedly positioned on the bearing 55 to permit adjustment of the frictional force. between the bearing and extension 60 It should be-understood that driving gear 57 is drivably' connected to agear train in arm section 33 in a manner identical to arm sectionas-a setscrew64q- The-arm 631preferably contains a re. gt e-hand grinhfi;torf cilitaterctatinattheiss rtfl It should be understood, however, that although a manual operating arm 63 has been shown for rotating the gear 57, the gear may be driven if desired by an electric motor or the like. t 7

It should be particularly noted and it is one of the important aspects of this invention when the knee rest 23 is positioned, as shown in Fig. 5, with the upper and lower rollers 42, 43in sliding engagement with the upper and lower rails 38, 37 on track 34, that the pinion 46 is held in meshing engagement with rack 39 and does not contact the inner surface of rail 37. It can be seen in Fig. 3 that when the leg rest 23 is in -the operating position perpendicular to the leg rest section 13, it is supported by contact of the rollers on opposite sides of track 34 with the forces being exerted in opposite directions.

In the operation of the table 11, together with the invention, the patient mounts the table by kneeling on the knee rest 23 with the lower part of his body in contact with the leg rest section 13. As previously discussed, the patient bends over the top 26 of the leg rest 13 and the table may then be tilted to the position of Fig. 2. However, it is necessary to insure that the bending of the patients body is at the proper position longitudinally so adjustment is made in the position of the knee rest 23 while the patient is supported thereon by rotating the hand crank 63 in the proper direction. This moves the knee rest 23 longitudinally of the leg rest section 13 as indicated by the double arrow H in Fig. 1 through the rotation of the pinion 46 along the rack 39 until the proper position of the patient is obtained. It should be understood that the weight of the patient does not affect the movement of the knee rest as the rollers 42, 43 permit the pinion 46 to move easily along track 34 even though the patient may be relatively heavy.

Another of the advantages of the construction of the knee rest is that no positive lock need be provided for any knee rest position seluted. The frictional forces in the knee rest gear trains and the additional frictional holding force exerted on the gear extension 60 by the adjustable bearing 55 produces a total holding force of suflicient magnitude to securely hold the knee rest in the adjusted position when the crank is released. In explanation of this fact it will be noted that a load on the knee rest tends to force the knee rest toward a non right angle relation with respect to the leg rest section. This causes a force on the upper roller 42 in a downward direction (as viewed in Fig. 3) and a force on the lower roll 43 in an upward direction. The action of these forces is such as to tightly grip the rail so that the gripping action increases as the weight on the knee rest increases. As there is a tendency for the knee rest to slide down due to the practically frictionless rollers 42, 43, the frictional forces described as necessary to overcome this movement.

Another of the outstanding features of the invention is the provision by which the knee rest 23 may be quickly and easily detached from the leg rest section 13 and suitably stored until its use is required. To detach the knee rest, the crank 63 is rotated in a counter-clockwise direction as viewed in Fig. 1 to move the knee rest upwardly. The pinion 46 travelling along rack 39 will eventually reach the top end of track 34 and can be easily disengaged from the rack permitting the knee rest to be removed. It can easily be seen that with the novel construction of the knee rest, the detaching of the knee rest from the leg rest 13 may be easily accomplished as the rollers 42, 43 do not interfere in any way. No other parts need be removed nor is any elaborate disassembly required.

It is necessary to provide a limit stop for the downward adjustment of the knee rest 23 for leg lengths. Continuous movement of the knee rest toward the lower end of the leg rest section would result in the upper roller 42 eventually leaving the upper rail 38 permitting the'knee rest to swing in the direction of arrow I as shown in Fig. 7 if such provision were not made. Inorder' to prevent this occurrence, the upper rail 38 on each track 34 is provided with a depression 74 and the lower rail- 37 with a notch 76. Each of the support arm sections 32, 33 contains an inwardly projecting pin 77 so that when the knee rest 23 is moved to the position of Fig. 6, the upper roller 42 will fall into the de pression 74 and the pin 77 will slip into the notch 76 with a resultant slight canting of the knee rest from the perpendicular. This position therefore represents the maximum leg length adjustment for the knee rest. However, 'the knee 'rest is releasably locked in this position, as the parts described have interlocked by virtue of the canting of the knee rest brought about by its own weight alone or together with the Weight of a patient. The knee rest may be released by merely tilting it back to the perpendicular and cranking it to the desired position.

Often it is desirable'in examination tables-of the type described to provide an arrangement whereby such a knee rest may be moved into the same plane as the leg rest section with which it is associated. This feature increases the overall length'of the table and permits the table'to be used for purposes where a long table is desirable The novel construction of the knee rest 23 permits this tablelengthening feature to be accomplished, as shown-in Figs. 7-9.

To locate the knee rest 23 in the table lengthening position of Figs. 8, 9, the knee rest is rotated back to the perpendicular position from the locking position of Fig. 6 and cranked further downward until it can be swung in the direction of arrow I as shown in Fig. 7. The upper roller 42 moves over and around the end of rail 38 while the pin 77 is withdrawn from the end of track 34. As the knee rest is swung further, the lower roller 43 supportingly engages the lower rail 37 as before and the shoulder in recessed-portions 41 in the sections 32, 33 engage the upper rail 38- to providea point of support 78 for the knee rest. The final position of the knee rest is shown clearly in Fig. 9 (in the same plane as the leg rest section 13) and it will be noted that the pinion 46 remains engaged with its rack 39.- In addition the knee rest ,23'is prevented from moving oif "the end of track 34 by a stop 79 suitably secured between the rails 37, 38 and containing a forward beveled edge 80 which engages the pinion 46 to limit its movement at the lower end of the track 34.

While the preferred form of the invention has been shown and described, it will be apparent that various changes and modifications may be made therein, partioularly in the form and relation of parts, without departing from the spirit of the invention as set forth in the appended claims.

We claim:

1. In a medical examination and operating table, the combination of a leg rest section and a knee rest section, a track on said leg rest section, at least two rollers carried by said leg rest section and engaging said track on opposite sides thereof for supporting said knee rest section in approximately right angle relation to each other, said leg rest section when the table is oriented for some uses extending in a downward direction, said track being open at its upper end so that the rollers may roll off the track without interference whereby the knee rest section can be freely separated from the leg rest section and stop means at the lower end of said track.

2. A table in accordance with claim 1 in which means are provided at the lower end of the track for rendering said stop means ineffective and means are provided enabling movement of the roller on the side of the track toward said knee rest to be shifted out of engagement with the track while the other roller remains in engagement with the track and assists in supporting said knee rest section in planar relation to said leg rest section.

A t b e in eeeeden w h 1 in whieh e reek, a p n n e a n s re k en e g Ta e ne er shi in sa nee re t along aid reeheed new are pto d fo a ju ing e *i tie i s d se tin .4- n a med ca e m natio n op ret h ab e he em at of a e Le se t 9n and a knee teet'see ien. i r k o d e e s et e et' eee tw i qllex 9 5-. e by said l rest ee e endehg e id'it ee 9 pp site d s her o pp rti e sa e kne est L n n approx m te y a s e e t section when he'tab e i 'q t d i "som s e end in e d w welsi d l e i n he ree 91, lse leg r s tio a p nio a n e sll eek means ine e h a t n of rs end e and epereted .erenk fer d i in a d pinion an en e iuet h eit etiph QQYiFe betweens d cran a d s d P ien A b e in e r e w e im liewhish lhe roller .e se i i e si e o he Heel; ie aed .the.: 29e e t e leee ed chee to the. pwer'endwet 3h; gee th hi he he x er- 6- A ta e n eee ene wi h eleise 1 jnyhish .1 19 e er e a i h de f h heels tewe d h es is eeet sl c o r h wer ens: 9f the h t e i l er h stop m elis e e rp eyisie he lower en e he re k Y 7- In a t bl t uc ur N h. eeinb netim 9, 5 e198 Fest and a knee rest, means for subportin' sgid' lgnge regton aid le r t n'sh s e t e y ht an e v e tie i h 9 e edii etin e n rest .e en 1 'e t m ih e h n ai h e, tw n sai k e e enieeid l IQ i 9l 9 9 ne y n a d e P ti n f ediueimeneeleps sa d e re e ekih me ns ne qin meene 95 ih reesr he the locking eifect of a d lee ih ihe wei ht n sa knee e is i r sed sa d es rg ent eeed ee ee empre ei e Pe e o e dre l meepe uvmlih epnes e s d which ,seid e er id seiMellete beih r n e so th a e h 9 s id kne re 's yee bo rollers to ex e P re e11 .se Ie l @ee e iz eti d r h an e el fie tefeeeh e her e re ation h p .e fl hei a d said m he en sub eef elly at ri ht al ele thereto.

111 e medical am t on hsi epe eti eh et e esmh e of a leg r s ien ens e We se e eels 99 sei lvles re t ee en ans earrie b sa kn e est e'v e en eh e'seeble with sa ac ie sup r hsse d 91 reetsee w n epp pxi t y right angle relation to said leg rest section, saidmreans comprising f e tyr :ml e e. Qn e ee d olle engaging h lowe eisie 9.? ei 1i ekepdh et er oi id rollers e gggi ng the gppeg' side ofsa id track, said rollers being pa ed lem; :eeid heel wi the' ppe roller spaced fili ihei elem; *e is i e' k r t Point of ppli n 9? ees! on eeiq kne e t vthen he owe o l 9 In a rpedicnr-exgn ination and operating table the e mbieeti e o e e n t ee t en n a k e e t n, i te ls'e ,sei leg este etie m t e by' s e see; eeetie nge eeb e i h eei track for pp r n sei kne re tf e ieyin eprpe mete y r ht g e l tion to said leg rest section,

said means comprising roller meehe n e ihs epnesi eeieee. efee sl tra k a ree a ieeeeteeid teem-Tend m ans ine ud gearing ee y ee' ke ei eet eeetieh end en e eeb w t d ee 9! e is eei kn re eeeiie lehsih id ne y'et sa 9s. eefiee' h the d eet e w th e pat e t kn l Q heeue tewtiee- 1 n'emed qe e e ihei enend operating table th e ,.i e 9! Q? a le re e et h d e knee'r s s c i n, a hee 9 ee si le res ee i e means carr d y said k seet en nd e geg e le w th sai ne f r supp xeelsihee he e r en 9P2 h hl ees b tween ee q' hee re se tio nd k ir1e =kin ee kn e rest sect a ains y m 9?? he 9m? end of ee i' ree 559E292. 9 i the le e thi P te UNITED STATES PATENTS 

